In general, windshield wipers for automobiles include a wiper blade removing foreign substances from a windshield of an automobile, a wiper arm connected to the wiper blade, and a driving unit rotating the wiper arm. The driving unit includes a driving motor, a worm wheel cooperating with the driving motor to rotate the wiper arm, and a park switch directly installed on the worm wheel and returning the wiper to a park position by supplying power to the driving motor even when the ignition is turned off. The park switch continuously supplies power to the driving unit when the wiper blade is not returned to the park position although the main power of the automobile is turned off, and discontinues the power supply to the driving unit when the wiper blade is returned to the park position.
When the windshield of the automobile is covered with snow and the main power of the automobile is turned off, the wiper blade is forced to return to the park position by the park switch but may fail to do so due to the snow. In this case, power is continuously supplied to the driving unit to rotate the wiper blade.
In particular, even when the wiper blade is stopped near the park position, power is continuously supplied to the driving unit. Thus, the wiper arm is elastically deformed, that is, is slightly bent, and does not reach the park position, and only the park switch is in an off state. When no power is supplied to the driving unit, the wiper arm rotates the driving unit in a reverse direction due to its elastic restoring force, and the park switch changes to an on state such that power is supplied to the driving unit again. Thus, the driving unit rotates slightly, and the park switch changes to the off state again. While the park switch repeatedly changes between the on and off states, a contact portion of the park switch may cause a spark, thereby damaging the park switch.